10 Worst Invasive Plants for a Southern Landscape

As a landscaper of over 20 years, there is so much I have
learned by simply walking into landscape after landscape. I have evolved as a
designer and, over the years, I have learned from my mistakes and the mistakes of
others. Sometimes you go by trends in landscaping, whether it is the up and
coming Bradford Pear tree or the beloved Nandina Domestica, sometimes it takes
time for a plant to really burn you, to best learn your lesson.

What are some of the qualifications to become one of the
worst plants?

Usually it is simply growth rate and the inability to
control it. Other factors include things like poor disease resistance, insect problems, immunity to herbicides or physical characteristics. Let’s
discuss some of my favorite plants to hate.

Pampas Grass, Cortaderia selloana is a great, terrible
plant. This ornamental grass becomes huge, swallowing everything in its path.
Is the Basketball missing? There is a good chance that it bounced into the
grass and may never be seen again. I have cut down many of these grasses, at a hefty
price to the customer, due to the fact that the edges of this grass are like
razor-wire and you can guarantee that you will be bleeding after an encounter
with it. I have also tried digging them out as well, which doesn't work.There are dwarf varieties of this grass, but with so many great
ornamental grasses out there, why even own one of these?

Variegated Privet, Ligustrum sinensis is such a hated plant
that most growers have stopped growing them and most nurseries have stopped
selling them. What makes this plant so awful is the fact that it can reproduce
sexually and asexually. That right, it produces seeds that birds eat and disperse
everywhere and it reproduces from root suckers, vegetatively. If you have
enough of these plants, they can grow faster than you can prune then.

The Bradford pear, like other pears, had to have a
pollinator to produce fruit. For so long this tree was not really producing
much fruit because there were not really many popular types of pears to
pollinate this tree. This changed as growers started to come up with “better”
cultivars that would not develop weak joints. Varieties like ‘Cleveland Select’,
‘Aristocrat’ and ‘Chanticleer’ were the solution.

These 4 varieties are all Callery pears and therefore, these
trees started cross pollinating with the millions of Bradford pears that were
over used. This produced inedible fruit that birds loved to eat. The birds would then start distributing the seeds everywhere.

The Callery pear rootstock was the tree of choice when it came
to grafting Bradford pears. The Callery pear itself is not so desirable as it
lacks the shape that comes with the Bradford and it has long, sharp thorns. When
Bradford pears were cut down they came back up, below the graft as this hideous
thorny pear. The seeds from the fruit are also that of the Callery pear.

This tree is now coming up everywhere. It is taking over
forests and killing off indigenous plants that other plants and animals count
on for shelter and food. Its ability to deal with shade or sun makes it
especially dangerous. If you see these trees coming up on your land, I would
recommend cutting it down and killing the stump because the problem gets exponentially
worse year after year.

English Ivy, Hedera helix, is considered an ecological
threat is some states and cost these states hundreds of millions of dollars to
battle. Here in Georgia, Kudzu is our English Ivy. This Plant cannot always be controlled
by Round-Up or Brush killers. The waxy layer on the plant prevents it from absorbing
these chemicals. This vine will also grow to the top of every tree in your yard
and anything else in its path. Once you have it, go ahead and plan yourself
some weekends for pulling up Ivy. This plant gets root hairs that will cling to
anything, helping it climb. It will grow to the top of a 100 foot tall tree,
shading its branches, over several years, putting a tree in decline and killing
it. This plant is banned in some states it is so bad.Click the orange link to learn How To Kill English Ivy.

Wisteria sinensis is one of the showiest plants on the list
of bad plants. When planted in the right place and given enough attention this
plant can put on quite a show. If you are not ready to adopt another child then
you are not ready for this plant, as this plant can become a “problem child”
quickly. This includes growing to the top of every huge tree in your yard and
even overtaking your lawn. The flowers bloom late winter and the woody vines
put on a great show but because it is a clingy vine, if you do not heed my
warning, plant it in wide open spaces and get ready to babysit.

Golden Bamboo, Phyllostachys aurea was brought to Alabama in
1882 and has taken over as far North as Maryland all the way to Florida. It is
a colonizing plant that sends out underground rhizomes and grows extremely
fast. This plant is extremely hard to kill with conventional herbicides and
often, soil sterilants have to come into play. It is said that it will get out
of control if not contained and it is also said that if you try to contain it,
you are destine to fail. That does not sound good, so just do not plant it. It
too is on everyone’s invasive species list.

Japanese Honeysuckle, Lonicera japonica is also a very
invasive, fragrant vine that is often found in some nurseries and garden centers. It has
adapted to be able to survive in full sun and heavy shade. If not controlled,
it will grow under and through all of your other bushes, making removal
impossible. It is very adaptable to different soil types, showing that this
plant is not really safe to plant much of anywhere. It too has landed itself of
most everyone’s invasive species list.

Nandina domestica, Heavenly Bamboo is considered to be so
problematic for the same reasons as the Privet. Underground rhizomes help this
plant spread vegetatively and birds spread the berries, putting this plant
everywhere that you don’t want it. This plant has been put on the invasive
species list in North Carolina, Georgia, Tennessee and Florida for that reason.
Covering the ground with weed block will prevent it for a little while, until
the weed block starts to break down.

Yarrow, Achellia is a fernlike perennial that will take over
a perennial bed and it will relentlessly spread its seeds and underground
rhizomes across your flower beds and into your yard. The real deal breaker with
this plant is that its seeds can live in the ground for 9 years, so there is no
getting rid of it once you have it. The best way to control this is by not
planting it ever and making sure that your neighbors follow suit. This plant
can handle any soil type as well. This plant will crush your spirits and haunt
your dreams.

Hybrid Bermuda grass and Common Bermuda Grass are last on
the list. Whereas landscapes can survive just fine without all these plants, all
yards need grass. It is good to know what you are dealing with when it comes to
dealing with Bermuda, as it is so popular in the south. Hybrid Bermuda grass
spreads incredibly fast with underground rhizomes and above ground runners that will try to crawl their
way into any area with sun on it. Hybrid grows lower and thicker and produces a
sterile seed head. Common Bermuda grows thinner, taller and produces a fertile
seed head; therefore it can reseed or spread via rhizomes. A self-repairing
lawn is a great thing to have, just be prepared to do some work around the
islands.